Make --disable-gpu-compositing disable browser compositor as well.

content/browser/gpu/compositor_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/gpu/compositor_util.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 43 matching lines @@
           command_line.HasSwitch(switches::kDisableAccelerated2dCanvas) ||
           !GpuDataManagerImpl::GetInstance()->
               GetGPUInfo().SupportsAccelerated2dCanvas(),
           "Accelerated 2D canvas is unavailable: either disabled at the command"
           " line or not supported by the current system.",
           true
       },
       {
           kGpuCompositingFeatureName,
           manager->IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_GPU_COMPOSITING),
-          false,
+          command_line.HasSwitch(switches::kDisableGpuCompositing),
           "Gpu compositing has been disabled, either via about:flags or"
           " command line. The browser will fall back to software compositing"
           " and hardware acceleration will be unavailable.",
           true
       },
       {
           kWebGLFeatureName,
           manager->IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_WEBGL),
           command_line.HasSwitch(switches::kDisableExperimentalWebGL),
           "WebGL has been disabled, either via about:flags or command line.",
@@ skipping 292 matching lines @@
   return problem_list;
 }
 
 base::Value* GetDriverBugWorkarounds() {
   base::ListValue* workaround_list = new base::ListValue();
   GpuDataManagerImpl::GetInstance()->GetDriverBugWorkarounds(workaround_list);
   return workaround_list;
 }
 
 }  // namespace content